New aqua one air pump?

[Allyloveshercatfish]

I don't know if this question goes in this area but here goes

I recently found an old aqua one battery air pump 250 from my last tank and put it in, new batteries and turned it on but it's making a SUPER loud noise?
The air flow also looks super strong and I'm not sure what's going on..
Any suggestions or experience?
I've also got the little blue shell thing on the end and I think it's taking a while for the air to go through but every minute or so a new strand of bubbles appears and that flow looks much better?

 

[Sarahlc10]

How did you go?

Did you ever find out why? I just bought this same pump new, and it sounds like a construction site when turned on. It's extremely loud, I'm wondering if it's faulty or this is normal for a battery operated pump.